CHUNG-WU LINLiu T.-Y.Lin C.-J.Hsu S.-M.2020-03-032020-03-0320050023-6837https://www.scopus.com/inward/record.uri?eid=2-s2.0-13444292012&doi=10.1038%2flabinvest.3700201&partnerID=40&md5=7134b45fa55e7db51cee43aa255e7d12https://scholars.lib.ntu.edu.tw/handle/123456789/468906Histiocytic necrotizing lymphadenopathy (HNL), a disease of unknown cause, is characterized pathologically by the presence of plasmacytoid dendritic cells (pDCs), which are frequently mixed with oligoclonal T cells (OTCs) and myeloid cells. Toll-like receptors (TLRs 1-10) are a family of pattern recognition receptors of DCs. To investigate the interactions between pDCs and T cells, and to look for an etiology of HNL, we studied 24 HNLs for the profile of TLRs. Transcripts of TLR7, a receptor on pDCs for single-stranded RNA, were found in every case, confirming the universal presence of pDCs. Transcripts of TLR9, another receptor on pDCs for microbial unmethylated CpG-rich DNA, were correlated with OTCs, implying T-cell expansion stimulated by TLR9+ pDCs in response to a microbe. Because PCRs for bacterial 16S rDNAs were negative in the lymph nodes, a bacterial origin seems unlikely, but a virus remains a possible candidate. The pDCs lacked the maturation marker CD83, which suggested ineffective stimulation of T cells and might account for the usually benign course of HNL. Taken together, these data illustrate a novel approach, based upon TLR transcript analysis, for the integration of pathology, immunology, and clinical findings of HNL.[SDGs]SDG3CD83 antigen; DNA 16S; RNA; toll like receptor; toll like receptor 7; toll like receptor 9; adolescent; adult; article; bone marrow cell; cell interaction; cell maturation; clinical article; CpG island; dendritic cell; female; human; Kikuchi disease; male; molecular recognition; polymerase chain reaction; priority journal; school child; T lymphocyte; T lymphocyte activation; Adolescent; Adult; Antigens, CD; Child; CpG Islands; Dendritic Cells; Female; Histiocytic Necrotizing Lymphadenitis; Humans; Immunohistochemistry; Male; Membrane Glycoproteins; Myeloid Cells; Receptors, Cell Surface; Reverse Transcriptase Polymerase Chain Reaction; T-Lymphocytes; Toll-Like Receptor 7; Toll-Like Receptor 9; Toll-Like Receptorsjournal article10.1038/labinvest.3700201155169712-s2.0-13444292012